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	hartrees
Energy at 0K	-154.265426
Energy at 298.15K	-154.268243
HF Energy	-153.656868
Nuclear repulsion energy	97.380162

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)
1	A_g	3246	3124
2	A_g	1514	1457
3	A_g	1105	1064
4	A_g	932	897
5	A_u	693	667
6	A_u	471	453
7	B_1g	769	740
8	B_1u	3233	3112
9	B_1u	1543	1485
10	B_1u	1032	993
11	B_2g	507	488
12	B_2u	3215	3094
13	B_2u	1247	1201
14	B_2u	709	683
15	B_3g	3200	3080
16	B_3g	1147	1104
17	B_3g	847	815
18	B_3u	548	528

Atom	y (Å)	z (Å)
C1	0.683	0.792
C2	0.683	-0.792
C3	-0.683	0.792
C4	-0.683	-0.792
H5	1.457	1.566
H6	1.457	-1.566
H7	-1.457	1.566
H8	-1.457	-1.566

	C1	C2	C3	C4	H5	H6	H7	H8
C1		1.5847	1.3664	2.0924	1.0941	2.4821	2.2754	3.1845
C2	1.5847		2.0924	1.3664	2.4821	1.0941	3.1845	2.2754
C3	1.3664	2.0924		1.5847	2.2754	3.1845	1.0941	2.4821
C4	2.0924	1.3664	1.5847		3.1845	2.2754	2.4821	1.0941
H5	1.0941	2.4821	2.2754	3.1845		3.1323	2.9132	4.2776
H6	2.4821	1.0941	3.1845	2.2754	3.1323		4.2776	2.9132
H7	2.2754	3.1845	1.0941	2.4821	2.9132	4.2776		3.1323
H8	3.1845	2.2754	2.4821	1.0941	4.2776	2.9132	3.1323

atom1	atom2	atom3	angle	atom1	atom2	atom3	angle
C1	C2	C4	90.000	C1	C2	H6	135.015
C1	C3	C4	90.000	C1	C3	H7	134.985
C2	C1	C3	90.000	C2	C1	H5	135.015
C2	C4	C3	90.000	C3	C1	H5	134.985
C4	C2	H6	134.985	C4	C3	H7	135.015

All results from a given calculation for C₄H₄ (cyclobutadiene)

using model chemistry: CCSD(T)/aug-cc-pVDZ

States and conformations

	Computational Chemistry Comparison and Benchmark DataBase Release 22 (May 2022) Standard Reference Database 101 National Institute of Standards and Technology
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All results from a given calculation for C4H4 (cyclobutadiene)

using model chemistry: CCSD(T)/aug-cc-pVDZ

States and conformations

All results from a given calculation for C₄H₄ (cyclobutadiene)